Answer:
Kf = 8.4 x 10²⁶
Explanation:
H₂S(aq) ⇌ HS⁻(aq) + H⁺(aq)
K1 = [HS⁻] [H⁺] / [H₂S]
K1 = 9.76×10−8
9.76×10−8 = [HS⁻] [H⁺] / [H₂S]
HS⁻(aq) ⇌ S²⁻(aq) + H⁺(aq)
K2 = 1.22×10−19
K2 = [S²⁻] [H⁺] / [HS⁻]
S²⁻ (aq) + 2H⁺(aq) ⇌ H₂S(aq)
Kf = [H₂S] /[S²⁻] [H⁺]²
To obtain the value of Kf, the relationship between Kf, k1 and k2 have to be determined;
K1K2 = ( [HS⁻] [H⁺] / [H₂S]) * [S²⁻] [H⁺] / [HS⁻]
K1K2 = [H⁺]² [S²⁻] / [H₂S]
K1K2 = 1 / Kf
Kf = 1 / (K1K2)
Kf = 1 / (9.76×10⁻⁸ * 1.22×10⁻¹⁹)
Kf = 1 / (11.91 x 10-27)
Kf = 0.084 x 10²⁸
Kf = 8.4 x 10²⁶
Answer:
[tex]K=8.40x10^{25}[/tex]
Explanation:
Hello,
In this case, the equilibrium constant is asked for the following reaction:
S2−+2H+⇌H2S
Thus, by means of the given equilibrium constants and reactions, a suitable combination results by:
1. Inverting:
H2S(aq)⇌HS−(aq)+H+(aq)
as
HS−(aq)+H+(aq) ⇌ H2S(aq)
2. Inverting:
HS−(aq)⇌S2−(aq)+H+(aq)
as
S2−(aq)+H+(aq)⇌HS−(aq)
Thus, by adding them we obtain:
HS−(aq)+H+(aq)+S2−(aq)+H+(aq)⇌HS−(aq)+H2S(aq)
Resulting in:
S2−(aq)+2H+(aq)⇌H2S(aq)
Which is simplified but proposing it law of mass action it turns out:
[tex]K=\frac{[H_2S]}{[HS^-][H^+]} *\frac{[HS^-]}{[S^{2-}][H^+]} = \frac{1}{K_1}*\frac{1}{K_2}=\frac{1}{9.76x10^{-8}} *\frac{1}{1.22x10^{-19}} =8.40x10^{25}[/tex]
Best regards.
